Here is the latest solution provided by Lenovo for those of you who are having problem with the webcam on the S10 or S10e after the firmware upgrade. You can download the latest firmware that solves the problem here but please read the release notes carefully before you take any action. I have reproduced the main points below and the most important point to note is not to do any firmware upgrade if you are not having any problem with your webcam.
After installing the Bison Camera Firmware Upgrade, the S10 camera will stop working and display only grey or black background.
Ideapad S10 can be equipped with two different camera sensors. The firmware upgrade available on the website, (version 1404) would damage the existing firmware of one of the cameras and cause the problem described above.
Important Note: This hotfix must ONLY be installed on the machines affected by the symptoms described above. If the camera is working properly, do not install this hotfix. Otherwise, the camera firmware will be destroyed permanently.
A new Firmware upgrade, version 1405, has been released and is available on the website in order to prevent the issue from happening."